Japan’s National Institute of Advanced Industrial Science and Technology (AIST) has developed a device that uses lasers to project real three-dimensional images in mid-air.  Cool photos.

The institute unveiled the device on February 7 in a demonstration
that showed off the device’s ability to project three-dimensional
shapes of white light.

AIST developed the projector with the cooperation of Keio University
and Burton Inc. (Kawasaki, Japan). Until now, projected
three-dimensional imagery has been “artificial” — optical illusions
that appear 3D due to the parallax difference between the eyes of the
observer. Prolonged viewing of this conventional sort of 3D imagery can
cause physical discomfort.

The newly developed device, however, creates “real” 3D images by
using laser light, which is focused through a lens at points in space
above the device, to create plasma emissions from the nitrogen and
oxygen in the air at the point of focus. Because plasma emission
continues for a short period of time, the device is able to create 3D
images by moving the point of focus.

At
the demonstration, bursts of laser light were emitted 100 times per
second to form shapes in the air up to 50 cm above the device. Heat
from the laser caused the air to expand, producing a crackling sound
that resembled a series of tiny explosions.

At the moment, the distance at which the device can project images
is limited to between 2 and 3 meters. Improved laser technology will
enable images to be projected at greater distances and with more color,
so we may soon see 3D images floating above our city skylines.

The chief scientist at AIST’s Photonics Research Institute says, “We
believe this technology may eventually be used in applications ranging
from pyrotechnics to outdoor advertising.”

More here.